(1) Field of the Invention
This invention generally relates to devices for pulling wire through conduit, such as conduit used by electrical contractors wiring a structure. More particularly, this invention relates to such a wire pulling device that is remotely controllable, preferably having wireless control.
(2) Description of Related Art including Information Disclosed 37 CFR 1.97 and 1.98.
Supplying buildings with electricity and communications capabilities involves threading wiring (lines or cabling) through conduit. Typically, the path that cable must travel through the conduit includes changes in elevation and turns around corners. Generally, the procedure used to run cable or “pull wire” involves first threading string or lightweight flattened “fish tape” through the entire length of conduit. The heavier pull-line is then attached to one end, and extended through the conduit by pulling the string or fish tape out of the conduit. Cabling is then attached to one end of the pull-line extending through the conduit, and pulled through the conduit as the pull-line is pulled out of the conduit.
The pulling force required can be significant depending on the weight of the cable and the distance traveled. The pulling force can also increase with the bends and turns in the conduit. Thus, there is a need to substitute machine force for human force to reduce the human strength and effort required in this procedure. Wire pulling devices have been available for a number of years.
At present, it requires two people to pull wire through the conduit intended to house the wire; after a pull-line has been run through the conduit (typically from the destination end to the end into which the wire will be introduced), and temporarily coupled to the wire, one person is needed to feed the wire into the conduit, and one person is needed to manually pull the pull-line back through the conduit to the destination end. The obvious benefit of the present invention is that the labor time is essentially cut in half by using just one person to accomplish both tasks. Often the wire will become tangled on its spool, making it necessary to stop pulling the pull-line until the wire can be untangled; alternatively, sometimes the wire encounters an angle or other obstruction preventing passage without further intervention (such as reducing the diameter of the coupling of the wire and the pull-line). When such stoppage occurs, often the two electricians or other workers are not within sight or earshot of each other, or cannot otherwise communicate readily with each other. The person feeding the wire customarily has to yank back on the wire to signal the other to stop pulling the pull-line. The worker pulling the pull-line typically has to leave the destination end and go find out why the pulling is stopped, and then return back to start pulling again after the cause of the stoppage has been cured. The valuable time of two workers is therefore squandered. Accordingly, there is a need for a wire pulling machine that is remotely controllable, preferably having wireless control.
Known in the art are the following patents, arguably related to the patentability of the present invention:
U.S. Pat. Nos.1st InventorDate of patent/Publication2,755,066Mallasch17 Jul. 19564,270,734Straight2 Jun. 19814,337,024Gebo6 Jul. 19824,497,470Carter5 Feb. 19854,917,362Wilson17 Apr. 19905,464,193Wrate7 Nov. 19956,293,520Turner25 Sep. 20016,682,050Ray27 Jan. 20046,691,985El Haddad17 Feb. 2004
U.S. Pat. No. 6,293,520 issued to Turner discloses a tram-like device for pulling an attached second overhead cable alongside a first overhead cable. The device includes a motorized body having a drive wheel that turns against the first cable to propel the cable puller along the first cable, dragging the attached second cable along. The cable puller also includes a receiver for receiving radio signaling from a transmitter held by the user, to control the movement of the cable puller to and from its destination point.
U.S. Pat. No. 4,917,362 issued to Wilson discloses an automatic wire puller for use with a standard tape reel having a play-out and take-up handle, the automatic wire puller including a bi-directional drive for selectively rotating the tape reel in a play-out (tape lengthening) or take-up (tape shortening) direction, and a wired means for remotely selecting the direction of operation and engaging the drive means. This patent also discloses a means for sensing torque on the tape reel, and disabling the drive means if the tape becomes snagged during take-up or if tape take-up is complete.
U.S. Pat. No. 4,270,734 issued to Straight discloses a winch powered by an electrical motor having an actuation button on the motor. After the winchline is threaded through the conduit and attached, to the wire to be pulled through the conduit, the winch button actuates the motor to rotate the winch drum; spooling of the winchline around the drum pulls the wire through the conduit and up to the drum, at which time the operator deactivates the motor.
U.S. Pat. No. 6,691,985 issued to El Haddad discloses a motor-driven shaft having wire (or a tether for wire) attached; rotation of the shaft essentially winds the wire (or tether) around the shaft, thereby pulling the wire into an electrical box. An actuator such as a foot operated pedal selectively turns the motor on and off.
None of the above listed patents discloses an apparatus for pulling a free end of wire into the mouth of a conduit and through the destination end of the conduit, including a wireless spooling controller in cooperating communication with a spooling machine and anchoring means for anchoring said spooling machine near the destination end of the conduit.